In a wireless radiotelephone communication system, many users communicate over a wireless channel. The use of code division multiple access (CDMA) modulation techniques is one of several techniques for facilitating communications in which a large number of system users are present. Other multiple access communication system techniques, such as time division multiple access (TDMA) and frequency division multiple access (FDMA) are known in the art. However, the spread spectrum modulation technique of CDMA has significant advantages over these modulation techniques for multiple access communication systems.
The CDMA technique has many advantages. An exemplary CDMA system is described in U.S. Pat. No. 4,901,307, entitled “Spread Spectrum Multiple Access Communication System Using Satellite Or Terrestrial Repeaters”, issued Feb. 13, 1990, assigned to the assignee of the present invention, and incorporated herein by reference. An exemplary CDMA system is further described in U.S. Pat. No. 5,103,459, entitled “System And Method For Generating Signal Waveforms In A CDMA Cellular Telephone System”, issued Apr. 7, 1992, assigned to the assignee of the present invention, and incorporated herein by reference.
In a typical system, several base stations are deployed to allow numerous mobile users to communicate with the base stations as they travel. The communications networks would typically include a base station controller or similar device that exchanges communications with multiple base stations. Examples of the communications networks include public switched networks, wireless networks, satellite networks, long distance telephone networks, local telephone networks, and the Internet.
A repeater may be used to extend the range of the base station. The repeater receives wireless signals from a base station and one or more mobile users. The repeater amplifies the received signals and transmits wireless signals based on the amplified signals to the base station and/or to the mobile users. As a result, the repeater extends the range of the base station. The base station also typically receives wireless signals from other mobile stations directly (i.e., without using the repeater).
Repeaters provide a cost-effective way for carriers and service providers to fill holes in the coverage area or to augment the area of coverage. However, the use of repeaters is hindered by daily and seasonal changes in the environment, which cause fluctuations in both the gain of the repeater and the path loss between the repeater and the base station. These fluctuations could adversely affect the coverage and service in repeater coverage area. There is a need, therefore, to control the gain of the repeater to stabilize the repeater coverage area.